METHOD FOR PRODUCEING A MACHINING SEGMENT FOR THE DRY MACHINING OF CONCRETE MATERIALS

Description

Technisches Gebiet

[0001] The present invention relates to a method for producing a machining segment according to claim 1. Stand der Technik

[0002] Machining tools, such as core drill bits, saw blades, grinding wheels, and abrasive chains, comprise machining segments that are attached to a tubular, disc-shaped, or ring-shaped base body, with the machining segments being connected to the base body by welding, brazing, or bonding. Depending on the machining process of the tool, machining segments used for core drilling are called drill segments, those used for sawing are called saw segments, those used for material removal are called material removal segments, and those used for abrasive cutting are called abrasive cutting segments.

[0003] Machining tools designed for wet machining of concrete materials, such as core drill bits, saw blades, grinding discs, or abrasive chains, are only conditionally suitable for dry machining. Wet machining of concrete materials produces an abrasive concrete slurry that aids the machining process and leads to self-sharpening of the machining segments during operation. The matrix material is removed by the abrasive drilling slurry, exposing new hard aggregate particles. Dry machining of concrete materials does not produce an abrasive drilling slurry to support the machining process. The hard aggregate particles dull quickly, and the machining rate decreases. Due to the lack of concrete slurry, the matrix material wears too slowly, and deeper hard aggregate particles cannot be exposed.In known wet machining tools, the matrix material and the hard material particles exhibit similar wear rates.

[0004] Machining segments for core drill bits, saw blades, grinding wheels, and abrasive chains are manufactured from a matrix material and hard particles. The hard particles can be statistically distributed or arranged in the matrix material according to a defined particle pattern. For machining segments with statistically distributed hard particles, the matrix material and the hard particles are mixed, the mixture is poured into a suitable mold, and then processed into the machining segment. For machining segments with fixed hard particles, a green compact is built up layer by layer from the matrix material, into which the hard particles are placed at defined positions.

[0005] WO 2008 / 091039 A1 and WO 2008 / 091040 A1 disclose a known method for manufacturing a machining segment. In a first step, a green compact is built up from a matrix material and hard particles, the hard particles being placed in the matrix material according to a defined particle pattern. In a second step, the green compact is compressed into a compact under pressure between a first press punch, which forms the underside of the machining segment, and a second press punch, which forms the top side of the machining segment opposite the underside. In a third step, the compact is further processed into the machining segment under the influence of heat.

[0006] US 6,045,750 A discloses known methods for producing a green compact for a machining segment. The green compact is built up from a matrix material and hard material particles, and the hard material particles are placed on a top surface of the green compact opposite the bottom surface in the first matrix material.

[0007] The known method for manufacturing a machining segment has the disadvantage that the hard material particles on the top side of the finished machining segment do not protrude. Darstellung der Erfindung

[0008] The object of the present invention is to develop a method for manufacturing a processing segment suitable for the dry processing of concrete materials. The processing segment should exhibit a high processing rate and the longest possible service life when dry processing concrete materials.

[0009] This problem is solved according to the invention in the aforementioned method by the features of independent claim 1. Advantageous embodiments are specified in the dependent claims.

[0010] The method for producing a machining segment from a first matrix material and first hard particles for a machining tool, wherein the machining segment is connected to a base body of the machining tool at an underside and the protrusion of at least one first hard particle relative to the first matrix material is greater than 400 µm, is characterized according to the invention in that, during the compaction of the green compact, a second press punch is used which has depressions in a pressing surface, the arrangement of which corresponds to the defined particle pattern of the first hard particles. By using a second press punch which has an arrangement of depressions for the first hard particles in the pressing surface, the green compact can be compacted into a compact with a protrusion of the first hard particles relative to the first matrix material on the top side.The depressions, which correspond to the defined particle pattern of the first hard material particles, are required to create the protrusion of the first hard material particles on the top side during pressing.

[0011] Machining segments produced using the inventive method are manufactured in a three-stage process: In a first stage, a green body is built up from the first matrix material and the first hard material particles, wherein the first hard material particles are placed in the first matrix material according to a defined particle pattern; in a second stage, the green body is compressed into a compact under pressure between a first press punch, which forms the underside of the machining segment, and a second press punch, which forms a top side of the machining segment opposite the underside; and in a third stage, the compact is further processed into the machining segment under the influence of temperature or by infiltration.

[0012] The inventive method enables the production of machining segments with a protrusion of the first hard material particles relative to the first matrix material, wherein the protrusion of at least one first hard material particle relative to the first matrix material is greater than 400 µm. Machining segments in which at least one of the first hard material particles has a protrusion of more than 400 µm relative to the first matrix material are suitable for the dry machining of concrete materials. The greater the protrusion of the first hard material particles, the higher the machining rate that can be achieved with the machining tool.

[0013] In a first preferred variant, a top layer of the first matrix material is applied after the initial placement of the first hard particles. This top layer ensures that the first hard particles are embedded sufficiently deep within the matrix material to guarantee adequate adhesion and prevent particle breakout in the finished machining segment. The thickness of this top layer is adjusted to meet specific requirements. Once the top layer completely embeds the hard particles, a second press ram is required to create a surface elevation of more than 400 µm above the matrix material.If the top layer does not completely embed the first hard material particles, the green body already has a protrusion of the first hard material particles relative to the first matrix material; however, the wear of the second press punch is greater than with completely embedded first hard material particles.

[0014] In a second preferred embodiment, after the initial placement of the hard particles, a top layer of a second matrix material is applied, wherein the second matrix material differs from the first. Applying a top layer of a second matrix material that differs from the first allows the use of matrix materials with varying wear properties. When the top layer completely embeds the initial hard particles, the finished machining segment has a protective layer on its upper surface. This protective layer is removed by sharpening the machining segments or during machining. In both cases, it is advantageous to use a second matrix material with a high wear rate, so that the initial hard particles can be quickly and easily exposed.

[0015] In a third preferred embodiment, after the initial placement of the hard material particles, a first top layer of the first matrix material and a second top layer of a second matrix material are applied, the second matrix material being different from the first. The first top layer of the first matrix material ensures that the initial hard material particles are embedded sufficiently deep within the first matrix material, and the second top layer of the second matrix material can serve as a protective layer for the second die. This protective layer is removed by sharpening the machining segments or during machining. In both cases, it is advantageous to use a second matrix material with a high wear rate so that the initial hard material particles can be quickly and easily exposed.

[0016] In a further development of the process, initial hard material particles are used that are encased in a coating material, where the coating material corresponds to the initial matrix material. The use of encased initial hard material particles has the advantage that the initial hard material particles do not come into direct contact with the second press punch, and wear on the second press punch can be reduced.

[0017] In an alternative development of the process, initial hard aggregate particles are used that are encased in a coating material, which differs from the initial matrix material. The use of encased initial hard aggregate particles has the advantage that the initial hard aggregate particles do not come into direct contact with the second press ram, thus reducing wear on the second press ram. When using a coating material different from the initial matrix material, matrix materials with varying wear properties can be employed. The coating material serves to protect the second press ram during compaction and should be removable as quickly as possible after the processing segment is completed, in order to expose the initial hard aggregate particles that process the concrete. Ausführungsbeispiele

[0018] Embodiments of the invention are described below with reference to the drawing. These are not necessarily intended to represent the embodiments to scale; rather, where useful for explanation, the drawing is schematic and / or slightly distorted. It should be noted that numerous modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention. The general idea of ​​the invention is not limited to the exact form or detail of the preferred embodiment shown and described below, or to an object that would be limited compared to the object claimed in the claims. For given dimensioning ranges, values ​​lying within the stated limits are also intended to be disclosed as limit values ​​and can be used and claimed as desired.For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions.

[0019] They show: FIG. 1A, B Two variants of a machining tool designed as a core drill bit; FIG. 2A, B Two variants of a machining tool designed as a saw blade; FIG. 3 A machining tool designed as a cutting disc; FIG. 4 A machining tool designed as a cutting chain; FIG. 5A-C A machining segment in a three-dimensional representation ( FIG. 5A ), in a view of a top surface ( FIG. 5B ) and in a view on a side surface ( FIG. 5C ); FIG. 6 the production of the machining segment of the FIGN. 5A-C according to the inventive method, wherein in a first stage a green compact is produced and in a second stage the green compact is compressed into a pressed compact; and FIGN. 7A-C some tool components used in the production of the machining segment of the FIGN. 5A-C be used.

[0020] FIGN. 1A , B Two variants of a machining tool designed as a core drill bit 10A, 10B are shown. The in FIG. 1A The core drill bit 10A shown here will be referred to as the first core drill bit and the one shown in FIG. 1B The core drill bit shown, 10B, is referred to as the second core drill bit; furthermore, the first and second core drill bits 10A, 10B are grouped together under the term "core drill bit".

[0021] The first core drill bit 10A comprises several machining segments. 11A, a tubular basic body 12A and a tool holder 13A.The machining segments 11A, used for core drilling, are also referred to as drill segments, and the tubular base body 12A is also referred to as the drill shaft. The drill segments 11A are firmly connected to the drill shaft 12A, for example by screws, adhesives, soldering, or welding.

[0022] The second core drill bit 10B includes a ring-shaped machining segment. 11B, a tubular basic body 12B and a tool holder 13B. The ring-shaped machining segment 11B, used for core drilling, is also referred to as a drill ring, and the tubular base body 12B is also referred to as a drill shank. The drill ring 11B is firmly connected to the drill shank 12B, for example by screws, adhesives, soldering, or welding.

[0023] The core drill bit 10A, 10B is connected to a core drilling machine via the tool holder 13A, 13B and rotated by the core drilling machine in one direction during drilling operation. 14 around an axis of rotation 15 driven. During the rotation of the core drill bit 10A, 10B around the axis of rotation 15, the core drill bit 10A, 10B is driven along a feed direction. 16 The core drill bit 10A, 10B moves into the workpiece to be machined, with the feed direction 16 running parallel to the axis of rotation 15. The core drill bit 10A, 10B creates a core and a borehole in the workpiece to be machined.

[0024] The drill shaft 12A, 12B is in the exemplary embodiment of the FIGN. 1A The drill shank 12A, 12B is formed in one piece, and the drill segments 11A or the drill ring 11B are fixedly connected to the drill shank 12A, 12B. Alternatively, the drill shank 12A, 12B can be formed in two pieces, consisting of a first drill shank section and a second drill shank section, wherein the drill segments 11A or the drill ring 11B are fixedly connected to the first drill shank section and the tool holder 13A, 13B is fixedly connected to the second drill shank section. The first and second drill shank sections are connected to each other via a detachable connection device. The detachable connection device is, for example, designed as a plug-and-turn connection, as described in EP 2 745 965 A1 or EP 2 745 966 ​​A1. The design of the drill shank as a one-piece or two-piece drill shank has no influence on the construction of the drill segments 11A or the drill ring 11B.

[0025] FIGN. 2A , B show two variants of a saw blade 20A, 20B trained machining tool. The in FIG. 2A The illustrated saw blade 20A will henceforth be referred to as the first saw blade and the one in FIG. 2B The illustrated saw blade 20B is referred to as the second saw blade; furthermore, the first and second saw blades 20A, 20B are grouped together under the term "saw blade".

[0026] The first saw blade 20A includes several machining segments. 21A, a disc-shaped base body 22A and a tool holder. The machining segments 21A, which are used for sawing, are also referred to as saw segments, and the disc-shaped base body 22A is also referred to as the main blade. The saw segments 21A are firmly connected to the main blade 22A, for example by screws, adhesives, soldering, or welding.

[0027] The second saw blade 20B includes several machining segments. 21B, a ring-shaped base body 22Band a tool holder. The machining segments 21B, which are used for sawing, are also referred to as saw segments, and the ring-shaped base body 22B is also referred to as a ring. The saw segments 21B are firmly connected to the ring 22B, for example by screws, adhesives, soldering, or welding.

[0028] The saw blade 20A, 20B is connected to a saw via the tool holder and rotated by the saw in one direction during sawing operation. 24 around an axis of rotation 25 The saw blade 20A, 20B is driven. During the rotation of the saw blade 20A, 20B about the axis of rotation 25, the saw blade 20A, 20B is moved along a feed direction, the feed direction being parallel to the longitudinal plane of the saw blade 20A, 20B. The saw blade 20A, 20B creates a saw slot in the workpiece to be machined.

[0029] FIG. 3 shows a disc used as a wear plate 30trained machining tool. The machining disc 30 comprises several machining segments. 31, a basic body 32 and a tool holder. The machining segments 31, which are used for material removal, are also referred to as material removal segments, and the disc-shaped base body 32 is also referred to as the cup. The material removal segments 31 are firmly connected to the cup 32, for example by screws, adhesives, soldering, or welding.

[0030] The removal disc 30 is connected to a tooling device via the tool holder and rotated by the tooling device in one direction during removal operation. 34 around an axis of rotation 35 The cutting disc 30 is driven. During its rotation about the axis of rotation 35, the cutting disc 30 is moved over a workpiece to be machined, with the movement being perpendicular to the axis of rotation 35. The cutting disc 30 removes material from the surface of the workpiece to be machined.

[0031] FIG. 4 shows a cutting chain 36 trained machining tool. The 36-piece abrasive chain comprises several machining segments. 37, several segment-shaped basic bodies 38 and several connecting links 39. The machining segments 37, which are used for abrasive cutting, are also referred to as abrasive cutting segments and the link-shaped base bodies 38 are also referred to as drive links.

[0032] The drive elements 38 are connected via the connecting elements 39. In the exemplary embodiment, the connecting elements 39 are connected to the drive elements 38 by means of rivets. The rivets allow the drive elements 38 to rotate relative to the connecting elements 39 about an axis of rotation that passes through the center of the rivets. The machining segments 37 are firmly connected to the drive elements 38, for example by screws, adhesives, soldering, or welding.

[0033] The abrasive cutting chain 36 is connected to a tool holder and driven by the tool in one direction of rotation during operation. As the abrasive cutting chain 36 rotates, it is moved into the workpiece being machined.

[0034] FIGN. 5A-C show a processing segment 41 in a three-dimensional representation ( FIG. 5A ), in a view of a top side of the machining segment 41 ( FIG. 5B ) and in a view of a side face of the editing segment 41 ( FIG. 5C ).

[0035] Machining segment 41 corresponds in structure and composition to machining segments 11A, 21A, 21B, 31, and 37; machining segment 11B, designed as a boring ring, differs from machining segment 41 by its ring-shaped structure. The machining segments may differ from one another in their dimensions and surface curvatures. The basic structure of the machining segments according to the invention is explained with reference to machining segment 41 and applies to machining segments 11A and 11B. FIGN. 1A , B, for the processing segments 21A, 21B of the FIGN. 2A , B, for processing segment 31 of the FIG. 3 and for processing segment 37 of the FIG. 4 .

[0036] Machining segment 41 consists of a machining zone 42 and a neutral zone 43The neutral zone 43 is required if the machining segment 41 is to be connected to the base body of a machining tool; for machining segments that are connected to the base body, for example by soldering or gluing, the neutral zone 43 can be omitted. The machining zone 42 is made of a first matrix material. 44 and first hard particles 45 constructed and the neutral zone 43 is made of a second matrix material 46 Constructed without hard particles.

[0037] The term "hard particles" encompasses all cutting materials for machining segments; this includes, in particular, individual hard particles, composite parts made of several hard particles, and coated or encapsulated hard particles. The term "matrix material" encompasses all materials used to construct machining segments into which hard particles can be embedded. Matrix materials can consist of a single material or be composed of a mixture of different materials.

[0038] Machining segments produced using the inventive method for manufacturing a machining segment have a layer with first hard material particles 45; no further layers with first hard material particles 45 are provided. The term "first hard material particles" refers to the hard material particles of the machining segment 41 that, after the machining segment has been manufactured, have a projection on their upper surface relative to the first matrix material 44. Hard material particles that are completely embedded in the first matrix material 44 of the machining segment 41 do not fall under the definition of the first hard material particles.

[0039] The processing segment 41 is connected to a subpage. 47connected to the base body of the machining tool. For core drilling and material removal machining segments, the underside of the machining segments is generally flat, whereas for sawing machining segments, the underside has a curve to allow the machining segments to be attached to the curved end face of the ring- or disc-shaped base body.

[0040] The first hard particles 45 are arranged in the first matrix material 44 according to a defined particle pattern ( FIG. 5B ) and point to one of the upper sides opposite the underside 47 48 The machining segment 41 has a projection T 1 relative to the first matrix material 44. In the exemplary embodiment of the FIGN. 5A-C The machining segment 41 comprises nine first hard material particles 45 that project from the top surface 48. The number of first hard material particles 45 and the defined particle pattern in which the first hard material particles 45 are arranged in the first matrix material 44 are adapted to the requirements of the machining segment 41. The first hard material particles 45 generally originate from a particle distribution characterized by a minimum diameter, a maximum diameter, and a mean diameter. Due to the particle distribution of the first hard material particles 45 between the minimum and maximum diameters, the projections of the first hard material particles 45 can vary accordingly. In the example according to the invention, all first hard material particles 45 have a projection of more than 400 µm relative to the surrounding first matrix material 44. The FIGN. 1A , B, FIGN. 2A , B, FIG. 3 und FIG. 4 The machining tools according to the invention, which are intended for machining concrete materials, have a defined direction of rotation. Viewed in the direction of rotation of the machining tool, a distinction can be made between a front area and a rear area of ​​a hard material particle 45. Due to its geometry with a flat underside, the machining segment 41 is suitable as a drilling segment for the core drill bit 10A. The direction of rotation 14 of the core drill bit 10A defines a front area. 51 and a rear area 52. The processing of concrete materials takes place in the frontal regions 51 of the first hard aggregate particles 45, and the processing rate depends significantly on the size of the protrusion of the first hard aggregate particles in the frontal regions 51. The first hard aggregate particles 45 exhibit a frontal protrusion in the frontal region 51. T front and a rear overhang in the rear area T back on, which are identical in the exemplary embodiment. Alternatively, the first hard material particles 45 can have different front projections T front and rear projections T back.

[0041] The production of the machining segment 41 is carried out using the method according to the invention in three stages: In a first stage, a green body is 53 In a second stage, the green compact 53 is produced and turned into a pressed compact. 54 The compact is then further processed in a third stage, forming part 54 of the compact, to the processing segment 41. FIG. 6 Figure 53 shows the green compact 53 and the pressed compact 54. The green compact 53 is built up from the first matrix material 44 and the first hard material particles 45; in addition, a cover layer is formed. 55a matrix material is applied. The first matrix material 44 or a second matrix material is suitable as the matrix material for the top layer. 56, which differs from the first matrix material 44.

[0042] The green compact 53 is compacted under pressure until the compact 54 essentially exhibits the final geometry of the machining segment 41. Suitable methods for applying pressure to the green compact 53 include, for example, cold pressing or hot pressing. In cold pressing, the green compact 53 is subjected solely to pressure, while in hot pressing, it is exposed to both pressure and temperature, up to approximately 200 °C. The compact 54 is then further processed under heat, for example, by sintering or infiltration, to form the machining segment 41.

[0043] FIGN. 7A-C The figures show some tool components used in the production of the machining segment 41 using the method according to the invention. The tool components include a lower die. 61, a die 62 and a top stamp 63, where the lower die 61 is also referred to as the first press die and the upper die 63 as the second press die. FIGN. 7B und 7C show the upper stamp 63 in detail.

[0044] The green part 53 is built up in the die 62, which has a cross-sectional area corresponding to the desired geometry of the green part 53. The die 62 has a first opening on the underside into which the lower punch 61 can be slid, and a second opening on the top into which the upper punch 63 can be slid. The upper punch 63 has recesses in its pressing surface. 64 on, whose arrangement corresponds to the defined particle pattern of the first hard particle 45.

[0045] The green compact 53 is built up from the bottom up. The first matrix material 44 is filled into the die 62 using a filling shoe until the desired fill level is reached. The first hard particles 45 are placed into the surface of the first matrix material 44 according to the defined particle pattern and embedded to the desired embedding depth. The finished green compact 53 is compacted into the pressed compact 54 under pressure using the lower punch 61 and the upper punch 63. The compaction of the green compact 53 into the pressed compact 54 is carried out using the special upper punch 63 in a pressing direction perpendicular to the cross-sectional area of ​​the green compact 53. The recesses 64 in the pressing surface of the upper punch 63 have an arrangement that corresponds to the defined particle pattern of the first hard particles 45.The special upper punch 63 can be used to create the processing segments 41, which are suitable for the dry processing of concrete materials. The recesses 64 are necessary to create the protrusion of the first hard material particles 45 on the upper surface 48 during pressing.

[0046] Direct contact between the first hard material particles 45 and the recesses 64 of the upper punch 63 can lead to increased wear of the upper punch 63. To reduce wear of the upper punch 63, direct contact between the first hard material particles 45 and the upper punch 63 should be avoided. Suitable measures include applying a matrix material as a cover layer and / or using coated first hard material particles 45.

[0047] After the first hard material particles 45 have been placed, a cover layer 55 of the first matrix material 45 can be applied. Alternatively, a cover layer 55 of the second matrix material 56 can be applied, the second matrix material 56 being different from the first matrix material 44. When using a second matrix material 56 that differs from the first matrix material 44, matrix materials with different wear properties can be used. The second matrix material 56 serves to protect the upper punch 63 during the compaction of the green compact 53 and should be removable as quickly as possible from the finished machining segment to expose the first hard material particles 45 that machine the substrate. A second matrix material 56 with a higher wear rate than the first matrix material 44 can be removed quickly.

[0048] The use of encapsulated first hard aggregate particles has the advantage that the first hard aggregate particles 45 do not come into direct contact with the upper punch 63, thus reducing wear on the upper punch 63. The first matrix material 44 can be used as the encapsulation material for the first hard aggregate particles 45. Alternatively, a second matrix material can be used as the encapsulation material for the first hard aggregate particles 45, with the second matrix material being different from the first matrix material 44. When using an encapsulation material different from the first matrix material 44, matrix materials with different wear properties can be used. The encapsulation material serves to protect the upper punch 63 during compaction and should be removable as quickly as possible at the end of the processing segment to expose the first hard aggregate particles 45, which process the concrete material.

[0049] Depending on the wear properties of the first matrix material 44, increased wear of the first matrix material 44 on the side surfaces of the machining segment 41 can occur during machining of a substrate due to friction with the substrate. This wear can be reduced by the addition of second hard material particles. The second hard material particles can be added to the first matrix material 44 as statistically distributed particles, or the second hard material particles can be placed in the first matrix material 44 according to a defined second particle pattern. The second hard material particles are placed particularly in the area of ​​the side surfaces of the machining segment 41.

Claims

1. Method for producing a machining segment (11A, 11B; 21A, 21B; 31; 37; 41) from a first matrix material (44) and first hard material particles (45) for a machining tool (10A, 10B; 20A, 20B; 30; 36), wherein the machining segment is connected by an underside (47) to a basic body (12A, 12B; 22A, 22B; 32; 38) of the machining tool (10A, 10B; 20A, 20B; 30; 36) and the projection (T1) at least of a first hard material particle with respect to the first matrix material is greater than 400 µm, with the following steps: • a green body (53) is built up from the first matrix material (44) and the first hard material particles (45), wherein the first hard material particles (45) are placed in the first matrix material (45) according to a defined particle pattern, • the green body (53) is compacted under the action of pressure between a first press punch (61), which forms the underside (47) of the machining segment, and a second press punch (63), which forms an upper side (48) of the machining segment opposite from the underside (47), in a pressing direction perpendicular to the cross-sectional area of the green body, to form a compact body (54) and • the compact body (54) is further processed under the action of temperature or by infiltration to form the machining segment (41), characterized in that a second press punch (63), which has depressions (64) in a pressing surface, is used when compacting the green body (53), the arrangement of the depressions (64) corresponding to the defined particle pattern of the first hard material particles (45).

2. Method according to Claim 1, characterized in that, after the placement of the first hard material particles (45), an outer layer (55) of the first matrix material (44) is applied.

3. Method according to Claim 1, characterized in that, after the placement of the first hard material particles (45), an outer layer (55) of a second matrix material (56) is applied, wherein the second matrix material (56) is different from the first matrix material (44).

4. Method according to Claim 1, characterized in that, after the placement of the first hard material particles (45), a first outer layer of the first matrix material (44) and a second outer layer of a second matrix material (56) are applied, wherein the second matrix material (56) is different from the first matrix material (44).

5. Method according to one of Claims 1 to 4, characterized in that first hard material particles (45) which are encased by a casing material are used, wherein the casing material corresponds to the first matrix material (44).

6. Method according to one of Claims 1 to 4, characterized in that first hard material particles (45) which are encased by a casing material are used, wherein the casing material is different from the first matrix material (44).